The assignee of the present invention designs and manufactures spacecraft or satellites for operation in, for example, geosynchronous and low earth orbits. Such communication satellites carry communication systems and antennas that are used to communicate with ground-based communication devices. An antenna reflector may be illuminated by an array of radiating elements, such as feed horns, that are coupled with a beamforming network (BFN). The BFN may include a waveguide slot array such as described in U.S. Pat. No. 6,476,772, assigned to the assignee of the present invention, and hereby incorporated in its entirety into the present application. Such a waveguide slot array may include a set of parallel waveguides having broad walls that include slots so as to form a two dimensional planar array of slots. The slots disposed on each parallel waveguide are spaced at half-waveguide wavelength (λg/2) intervals along the waveguide length and adjacent slots are positioned on opposite sides of the centerline of the waveguide.
Improvements in the BFN that permit dual polarized and/or dual band operation in a more compact structure are desirable.